The top three things that lead one to failure are indecision, doubt, and fear. Doubt and indecision are mostly related, they are routines of not getting to your ideas faster and change them slowly as you progress. Indecision is a child of procrastination, and it's widely known that procrastination is a very bad habit. Procrastination is, I will do what I was supposed to last two years this year which will also be postponed to another year.
Fear is the state of the mind, though no one is completely fearless at least we should have the courage to try out new things. They say that the point of maximum danger is the point of minimum fear.